1. Field of the Invention
The present invention relates generally to wireless telecommunications networks and, more specifically, to geotagging digital photographs transmitted via a wireless mobile telecommunications network.
2. Description of the Related Art
Geotagging, also referred to as geocoding, is the process of adding geographical identification metadata to digital data files or data sources. The data file can represent any medium, with an image (e.g., photograph) being the most common. This data generally includes a geographic location in the form of latitude and longitude coordinates, but can also include a place name, altitude and other characteristics of a specific location. In theory, every part of a digital photograph can be tied to a geographic location, but in most instances only the position of the camera is associated with the entire digital image.
The most common method for geotagging a digital photo involves using a Global Positioning System (GPS) receiver. When a photo is taken, the location of the camera is recorded as digital data along with the digital data representing the image itself. Although there is currently no universal geotagging standard, some well-known digital image file format standards do specify formats for storing geographical coordinates along with the digital data representing the image. For example, the Joint Photographic Experts Group (JPEG) and Tagged Image File Format (TIFF) standards specify that geographical coordinates can be included in an Exchangeable Image File Format (EXIF) header. The EXIF header is commonly used in digital cameras to record the date and time a photo was taken. Although commercially available digital cameras generally do not contain a built-in GPS receiver, the photographer can use an external GPS device to identify and keep track of the location and time at which each photograph was taken, and later use commercially available software to incorporate the locations into the JPEG or TIFF files. A few specialized digital cameras have been developed that can be electronically connected to an external GPS receiver to facilitate geotagging photos.
Photographers often desire to upload their digital photos to a remote server computer. A photographer can upload photos by coupling the digital camera to a (client) computer with a cable or other local communication link and then uploading the photos from the client to the server via a network such as the Internet. It is also common for users of wireless mobile telecommunications network user equipment (UE) that include built-in digital cameras (sometimes referred to as “camera phones”) to upload photos taken with the UE via the wireless telecommunications network. The wireless telecommunications network service provider typically provides a server on which the user can at least temporarily store the uploaded photos and with which the user can transfer them via the Internet to other computers, such as a server operated by a third-party photo hosting service or the user's home computer. It is also known to couple a digital camera to a UE via a cable, wireless local area network (WLAN) link such as WIFI, or wireless personal area network (WPAN) link such as BLUETOOTH, and upload the images from the camera to the wireless telecommunications network via the UE.
It is known to geotag uploaded photos, including photos taken with camera phones or similar UE. Yahoo!, Inc., which provides the FLICKR Internet photo hosting service, has developed a geotagging client application (software) known as ZONETAG that runs on camera phones and operates in conjunction with Yahoo!'s FLICKR photo uploader utility and service. A user can access FLICKR to view and manipulate uploaded photos via the Internet. When a user indicates through the ZONETAG application that a photo is to be uploaded, ZONETAG determines the identity of the cell (i.e., base station) through which the camera phone or other UE is then communicating with the network and tags the photo with an identifier that identifies the network and cell (“Cell ID”) before uploading it to FLICKR. Once the photo has been uploaded, FLICKR attempts to translate the identifier into a geographic location. FLICKR has several ways in which it can gather information to assist it with the translation. When the user chooses to upload the photo, the user can enter a city name or ZIP code, which ZONETAG causes the camera phone to transmit along with the photo. Alternatively, the user can access FLICKR via the Internet and enter a ZIP code associated with the location where the user knows the photo was taken. The FLICKR server maintains a database that relates cell identifiers to city names, ZIP codes or other such identifying information. If a FLICKR user enters the city, ZIP code, etc., at which a photo was taken, FLICKR applies that information to not only that photo but also to other photos that the user may have taken within that same cell (i.e., that bear the same identifier) as well as the photos of other FLICKR users that were taken within that cell.
Wireless telecommunications network technologies such as General Packet Radio Service (GPRS) and Multimedia Messaging Service (MMS) have made it easier than ever for users to upload photographs from their UE. In a network employing such technologies, a received MMS message that includes a photo is routed to a Multimedia Messaging Service Center (MMSC), which performs many of the functions necessary to forward and otherwise handle the image.
The geographic location of a UE can be determined to an accuracy level greater than that defined merely by the cell in which the UE is located. The earliest use of sub-cell-level UE location related to emergency calling (e.g., the E911 system used in the United States), in which the network determines with sub-cell accuracy the location of a caller's phone and routes the call to an emergency operator who can, if necessary, dispatch emergency personnel to the user's location. Location-Based Services (LBS) are now expanding far beyond emergency calling, to such diverse uses as navigation, mapping, tracking and gaming.
Cell phones generally do not include built-in full-function GPS receivers because the phone would be undesirably large, and use of the GPS receiver would rapidly drain the cell phone battery. One common method by which UE location can be determined is known as Assisted GPS (A-GPS). An A-GPS-enabled UE contains a limited processing power GPS receiver, which is smaller and more power-efficient than a full-function GPS receiver. In A-GPS, the wireless telecommunications network transmits “assistance data” to the UE to aid the UE GPS receiver in finding and utilizing signals transmitted by the GPS satellites, as the GPS satellite signals that reach the receiver are sometimes weak or few in number due to shielding and reflection from buildings or terrain and, to the extent they can be detected at all, would otherwise require the processing power of a full-function GPS receiver to establish a location using them. As minimizing size and weight and maximizing battery charge conservation remain important goals for producers of cell phones, incorporating a more powerful GPS receiver capable of rapidly determining location without assistance data is not considered a commercially viable option. Some cell phones whose designs emphasize portability and battery conservation simply do not include even a limited processing power GPS receiver. Nevertheless, A-GPS is only one method by which a network can determine UE location. Other methods are based upon triangulation from known locations of base stations. Examples of such triangulation methods include Time Difference of Arrival (TDOA), Angle of Arrival (AOA), Forward Link Trilateration (FLT), Observed Time Difference (OTD). In networks generally of the Global System for Mobile telecommunications (GSM) and Universal Mobile Telecommunications System (UMTS) types, the network element that responds to an LBS query by determining the user equipment location is known as a Gateway Mobile Location Center (GMLC).
It would be desirable to provide a method and system for geotagging photos in a wireless telecommunications network that does not require the UE to determine its own location and tag its photos, thereby conserving battery and processing power and other resources. It is to the provision of such a method and system that the present invention is directed.